The US Food and Drug Administration (FDA) has released an updated and final list of pathogens that are eligible for special incentives under the 2012 Generating Antibiotics Incentives Now (GAIN) provisions of the Food and Drug Administration Safety and Innovation Act (FDASIA).

Background

The GAIN Act was passed in an attempt to incentivize the development of new antibiotics—a response to both growing rates of microbial resistance to antibiotics and a dearth of new antibiotic products in manufacturers' pipelines.

One of the GAIN Act's main provisions is Section 505E, which grants companies an additional five years of market exclusivity if they develop an antibiotic intended for a "qualified infectious disease." However, the act failed to describe which diseases are "qualified," leaving that distinction up to FDA regulators.

The statute laid out some, but not all, qualifications. For example, a "qualifying pathogen" had to be one with the "potential to pose a serious threat to public health." Legislators had identified gram-positive pathogens, multi-drug resistant gram-negative bacteria, multi-drug resistant tuberculosis (TB) and Clostridium difficile (c-diff) as being definite additions to the list, but left it up to FDA to generate a more exhaustive one.

For more on the GAIN Act and Qualified Infection Diseases, please see Focus' 11 June 2013 story, "FDA Looks to Spur Antibiotic Drug Development by Adding 18 Pathogens to Incentives List."

Draft Rule: Summary

In June 2013, FDA releases a proposed rule listing 18 pathogens which, if targeted by a product, would qualify a product for GAIN Act incentives like additional market exclusivity.

Those qualifying pathogens were as follows:

1. Acinetobacter species
2. Aspergillus species
3. Burkholderia cepacia complex
4. Campylobacter species
5. Candida species
6. Clostridium difficile
7. Enterobacteriaceae
8. Enterococcus species
9. Mycobacterium tuberculosis complex
10. Neisseria gonorrhoeae
11. Neisseria meningitidis
12. non-tuberculous mycobacteria species
13. Pseudomonas species.
14. Staphylococcus aureus
15. Streptococcus agalactiae
16. Streptococcus pneumoniae
17. Streptococcus pyogenes
18. Vibrio cholerae

Final Rule

However, FDA has now released a final rule amending that list, adding several pathogens that were not in its draft form.

The three new qualifying pathogens are:

1. Coccidioides species
2. Cryptococcus species
3. Helicobacter pylori

All 18 of the draft pathogens remain on the list.

Impact Uncertain

However, the impact of the list is not necessarily uniform. The language of the GAIN Act does not explicitly state that all products intended to treat qualifying pathogens are automatically eligible for Qualified Infectious Disease Product (QIDP), and neither does it prevent products intended to treat non-qualifying infectious diseases from obtaining QIDP status.

The QIDP status operates on a separate definition, and products eligible for the status are those which are “antibacterial or antifungal drug[s] for human use intended to treat serious or life-threatening infections."

FDA said its hands were tied by the statute, and that there was little it could do. As it explained:

"Qualifying pathogens are “pathogen[s]… that ha[ve] the potential to pose a serious threat to public health,” whereas QIDPs are certain human “drugs…intended to treat serious or life-threatening infections” (emphasis added). Most importantly, many pathogens with the potential to seriously threaten public health may cause varying levels of morbidity and mortality in a given individual depending on the site of infection, the person infected, the level of antimicrobial resistance present in the infecting pathogen, and other factors."

At least one commenter said the effect of this is to undermine congressional intent, and argued that the qualifying infectious pathogens list was intended to create certainty for manufacturers seeking to develop antibiotic therapies.

On Vaccines …

The final rule also determines that vaccine products are ineligible for consideration for QIDP designation under the GAIN Act due to their regulation under the Public Health Service Act (PHSA), and not the Federal Food, Drug and Cosmetic Act (FD&C Act).

Federal Register Notice: Food and Drug Administration Safety and Innovation Act: List of Qualifying Pathogens